Spark-plug.



FRANK DANIELSON, 0F CHICAGO, ILLINOIS.

SPARK-Prine.

Specification of Letters Patent.

' Patented Dec. 3, 191s.

Application filed August 19, 1916. Serial No. 115,845.

y To all whom 'it may concern:

Be it known that I, FRANKf DANmLsoN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Spark-Plugs, of lwhich the following is a full, clear, and exact description. y

My invention relates to spark plugs for explosive engines, -and particularly to that type of tubular metallic spark plugs having an electrode depending from its inner annular edge, and having another electrode depending` from an insulated core extending axially in said plug. Heretofore these electrodes have been so constructed that they were incapable of retaining gasolene, and priming was accomplished by injecting the gasolene directly into the cylinder in such manner that the electrodes were simply exteriorly moistened or not affected by the injection at all.

One of the conditions that contributes to the effectiveness of spark-plugs now in extensive use in explosive .engines is the incandescence of the electrodes. This requires the presence of gaseous vapors at the point where the spark passes from electrode to electrode, and the consequent ignition thereof. The common form of sparleplug, however, is so constructed that its lower end is .open and solid carbon forms in this opening and materially affects its usefulness.

One of the objects of my invention is to provide as large an incandescent electrode as possible and to prevent the accumulation of carbon in the lower end of the plug. Another object is to provide means for priming the plug and enable it to hold the initial charge of explosive fluid where it can be readily ignited to start the engine and retain a suiiicient quantity thereof where it will vaporize as 'the electrode becomes heated and enrich the explosive gas at the point where the ignition takes place duringthe initial explosions of the engine. These and other objects I accomplish by the means hereinafter fully described, and as more particularly pointed out in the claims, reference being had to the accompanying drawings forming a part of this specification, in which- Figure 1 is a side elevation of my improved spark-plug. Fig. 2 is a vertical central section of the same.

Referring more particularly to Fig. 2 of the drawings, it will be observed that this priming plug consists of a substantially hollow cylindrical metallic retainer or plug 1. The lower portion of this retainer is eX- teriorly screw-threaded and is adapted to be screwed into a. suit-able opening in the cylinder of a gas engine, and its lower another suitable insulating material, is insert-l ed therein.

At a point just below its center of length, this porcelain body is increased in diameter and the shoulder 6 at the lower, end of this widened portion is seated on a shoulder made by increasing the upper portion of the bore of the plug, as hereinbcfore stated, and said body is locked in this position i'n the The upper end of the bore plug by a suitable glandnut 7 that screws into the upper end of the same and engages the interior screw-threads thereof. y T he upper end of the porcelain body is protected 1 by a cap 4; which has a downwardly extend-` ing annular flange which is seated in the rabbeted upper edge of said body.

Body 3 has a longitudinal bore extending therethrough the lower portion of which (commencing at a point within the widest portion of the plug) is wider than the up'- per portion thereof. A tubular metallic electrode 8 is inserted through the said bore which is of such length that its ends extend beyond the ends of the body, and is of such diameter that its upper portion contacts with the walls of said bore while its lower portion is separated therefrom. `lust below the point where the bore of the body is increased in diameter, the electrode is eX- panded in any suitable manner to form a boss 9 and cap 4 is screwed onto the upper screw-threaded portion of the same to clamp it in the body between said boss and cap and to immovably secure it in its proper assembled position. Electrode 8 extends down below the lower ends of both the body and'plug 1, and a short distance below the latter has an inverted mushroom-shaped the screw head 10 removably secured thereto by means of a screw 11, which screws up into the lower end of the bore of the electrode and closes the lower end thereof. Head 10 may be made integral with the lower end of the electrode, if desired, but I prefer to make it removable so that, when oxidation wears away its edge opposite electrodes 2, 2, can be loosened and the head turned until an unaffected portion of the edge thereofis opposite said electrodes 2,12, and the proper distance between the two electrodes is restablished, or a new head substituted therefor. The diameter of this head is, preferably, slightly less than the lower end of the bore of plug 1, and its upper side is concaved and its under side convexed, substantially as shown in the drawings. i

J ust below boss 7 and well up in the lower wider portion of the trode 8 is forations 12, so that when gasolene is poured down into said electrode 8 the portion thereof below boss 9 will constitute a well that will retain a small portion of gasolene before it overflows out through perforations 12 and gravitates down into the annular gutter formed by' the upper concaved side of .head 10 and iills the same.y

The upper screw-threaded end of electrode.

8 extends above cap et and has acup or basin 16 screwed thereon. This cup or basin comprises a casing 14 the bore in the base of which is in axial alinement with that of electrode 8. The upper end of theborc of the basin is made funnel-shaped to provide a valve-seat 19, and the central portion of said basin has a tubular member 17 extending vertically therefrom that is interiorly thread ed and engaged by a needle-valve 18, whose lower tapered end is adapted to engage said funnel-shaped valve-seat 19. Just above the bottom of the basintubular member 17 has one or more inlet ports 20 therein through which the gasolene can, when the needle- .valve has been moved upward, How from the basin into the electrode.

ln operation, needle-valve 18 is turned so as to close the bore of the casing when gaso lene is poured into the basin. The said valve is then turned in the opposite direction to open said bore and to permit the gasolene to flow down into the tubular electrode and through'the apertures therein into the annular gutter of the head. Any excess of gasolene will flow over the edges of the head and into vthe cylinder. Whenthc valve is moved to close the bore engine cranked7 the sparks will pass between the edge of head 10 of electrode 8 and electrodes 2 and ignite the gasolene held by said head, at the same time exploding the gaseous vapors within the cylinder. As the engine continues to operate, head 10 becomes bore of the body, elecprovided with one or more pery of the electrode andtheV of said body the lower end of which incandescent and the gasolene within the well or lower portion of the bore of elecytrode 8 will vaporize and be forced down around the annular edge of head 10 and enrich the mixture of gas at the point where the spark occurs and do this for the first four or five hundred explosions after the engine is started at the point where most needed. The explosions in the cylinder below said head are deflected by the convexed underside of the same so that the spent products of explosions will not enter the chamber formed in the lower end of the plug above said head and permit carbon to accumulate therein and close perforations 12 of the tubular electrode, or short circuit said electrode 8 and the walls of the bore of plug 1.

What I claim as new is 1. A spark-plug for explosive engines comprising a suitable metallic plug having electrodes connected with and dependingfrom the lower end thereof, a tubular body or barrel of suitable insulating material retained thereby, an axially disposed tubular electrode supported within the bore of said body through which gasolene can be passed, which is closed at its intake cnd while the engine is in operation the lower end of which extends below the lower end of said plug and has a screw-threaded bore ated closure for the upper end ofthe bore thereof, a concavo-convex head, and a screw that engages said bore and retains said head on the lower end of said axial electrode. i 100 2. A spark-plug .for explosive engines comprising a suitable plug, a suitable metal-- lic electrode connected. with and depending from its lower annular edge, a tubular body or barrel of insulating` material retained thereby, an axially disposed tubular electrode supported within the bore of said body the lower end of which extends below the lower end of the plug and which has a cup or basin supported by the upper end of said axially disposed electrode having a tubular member projecting centrally from the bottom thereof, a needle-valve engaging the' screw-threaded bore of said tubular member and engaginga suitable valve-seat inthe 115 bottomof said basin for controlling the discharge therefrom into said electrode, and a head having aconcaved upper side secured to the lower end of said electrode and closing the bore thereof.

3. A spark-plug for explosive engines comprising a suitable plug. a suitable metallic electrode connected With and depending from its lower annular edge, a tubular body or barrel of insulating material retained 125 thereby thelower portion of the bore of which is greater in diameter than that of the upper portion thereof, an axially disposed tubular electrode supported Within the bore extends 130 below the lower end of the plug and which trode, and e head having a concaved upper 10 has a cup or basin supported by the upper side secured to the lower end of seid elecend of said axially disposed electrode havtrode and closing the bore thereof. ing a tubular member projecting centrally In Witness whereof I have hereunto set 5 from the bottom thereof, e needle-valve enmy hand this 17th dey of Au ust, 1916.

gaging the screw-threaded bore of said tubu- FRANK DA IELSON. lar member end engaging a suitable valve- Witnesses:

seat in the bottom of said basin for control- WM. DANIELSON,

ling the discharge therefrom into said elec- BENTON GARvxN. 

